The cartilage defects at joints caused by trauma or osteopathia are common clinical diseases, which severely affect the life quality of the patients, and have become one of the main reasons of physical disabilities. In US, the incidence rate is 1.5‰-3‰; while in China, the incidence rate is about 5-6 times of US and is rising gradually year by year. Joint cartilage belongs to hyaline cartilage, which lacks of neurovascular nutrition and is hard to self-heal. Current clinical treatment measures all have substantial deficiencies. For instance, conservative therapy and joint debridement can only temporarily relief the pain, but cannot stop the disease progress. Autologous osteochondral transplantation can lead to donor site damage, and has difficulty to repair larger area defect due to limited source. Allograft osteochondral transplantation may have the possibility of immunological rejection and disease spreading. Artificial joint replacement is rather expensive, may lead to more complications, has higher revision rate, and especially has big physical and mental effects and heavy financial burden on the young patients.
Emerge and rapid development of tissue engineering provide a new technology for regenerative repair of joint cartilage. Three-dimensional scaffold provided by tissue engineering scaffold material for constructing cell of the tissue facilitates cell adhesion, cell proliferation and cell differentiation, which provides suitable external environment for cell growth. In tissue engineering, the scaffold material acts as extracellular matrix, and simulates structure and function of extracellular matrix. The scaffold material not only provides support to keep the shape of original tissue, but also acts as a template to provide a site for cells to board, grow, differentiate and proliferate, so as to guide the impaired tissues to regenerate and to control structure of the regenerated tissues.
The prepared type II collagen, upon mixed with hydrochloric acid solution, will be sealed and packaged for store. When needed, the type II collagen-hydrochloric acid solution is first to be neutralized, and then the prepared BMSCs will be moved into the type II collagen-hydrochloric acid solution, which upon fully mixed, centrifuged to remove bubbles, will be suctioned into a vacuum needle for use. Currently, there is no special in vitro construction apparatus for injectable tissue engineered cartilage available, and such apparatus is manually prepared by medical staff, which adds burden to the medical staff. Further, the prepared injectable tissue engineered cartilage has low acceptability, causing unnecessary waste of material.